Tuesday, 1 December 2015

In the upcoming issue of ACM interactions magazine I will talk in my column on interaction technology about the electrical interfaces to humans.
This blogpost is written to give you a preview of the article and describes a little project I did over the weekend to explore Electromyography (EMG).

It is the simplest circuit I could find and it results in a very simple and easy to make EMG. It takes less than half an hour to build and plugs into the microphone input of a computer. It uses a single operation amplifier (INA128p) and is based on the description in [1]. Builing the filter into the gain branch is quite nice ;-)

The eagle CAD file is available for download. Connecting it to other parts of the body made a very simple ECG – more suitable to get the heard rate that the shape of the signal.

More sophisticated circuits are available, e.g. openBCI [2] or an EMG shield for Arduino [3]. If you look more for commercial device you will find in [4] a good overview and also an introduction to emotion sensing.